Alternator Voltages

[Shtudwn]

Hi,

I have just replaced my battery and now I am suspect of my alternator.

I have 14.3V at idle with nothing on but as soon as I put a load on the system such as heater, lights, wipers, and turn signal....wow! I'm at 12 volts. is that common? Can't drive much at night in the rain!

Is the alternator week?

Thank you.

[slorio]

Shtudwn:
What is the voltage at the battery when you rev the engine off of idle with the lights, heater, etc. on? System should be able to produce 13.5 volts under such a load, but not unless engine is up above idle to an operating speed. Are you using a volt meter to read the voltage or are you depending on a factory gauge in the panel. Factory gauges aren't very accurate.

Hope that helps.
Regards,
Steve
New Orleans

[Shtudwn]

Thank you Steve!

I reved the engine while checking the voltage. With everything on i'm getting above 14V. Yes!

[Wrenchbender Ret]

Those readings are normal. Your alt is working good. Some of those early alt. did not have a high amps output. It may be a 42 amp. You can use a 55 amp. with external regulator or even higher with an internal regulator.

[slepysal]

I recommend you install the headlight relays, they will take a load off the charging system

[Wrenchbender Ret]

Originally Posted by slepysal

I recommend you install the headlight relays, they will take a load off the charging system

Headlight relays are a good idea but the lights will still have as much load on the bat. & charging system. The lights will brighter & it will take the load off the light switches.